Currently, packaging techniques for semiconductor devices, such as transistors, integrated circuits, or opto-electrical devices including light-emitting diodes (LEDs) and laser diodes (LDs), include using glue or silver solder paste to connect semiconductor chips and frames or sub-mounts while flip-chip techniques are performed by using metal bumps to connect semiconductor chips and package substrates or frames. The glue or silver solder paste is usually mixed with polymer materials to provide viscosity.
The glue or solder paste is usually mixed with polymer materials, so that the thermal conductivity of the glue or silver solder paste is much lower than those of metals, and the heat-dissipating efficiency of semiconductor devices is obviously poor. In the flip-chip techniques, alloys, such as AuSn, are used as the materials of the metal bumps, however, the thermal conductivity of the alloys still cannot fulfill the high heat-dissipating requirements of the semiconductor devices.
In addition, in the process of fixing the semiconductor chips with glue and solder paste or in the flip-chip package processes, the process temperature has to be increased to above 150° C., even above 200° C. in the flip-chip package processes. During the thermal connection processes at this temperature, the semiconductor device properties are easily damaged, thereby degrading the operation stability and quality of the semiconductor devices. Furthermore, the connection of fixing the chips takes at least three hours from coating the glue, disposing chips, to baking the glue.
According to the aforementioned description, after the semiconductor chip and the package substrate are connected by the conventional techniques, the heat-dissipating ability of the whole semiconductor device is poor. Many issues are caused by the poor heat-dissipating property of the whole semiconductor device. For example, the semiconductor device cannot be operated with high power, and the inherent properties of the semiconductor device cannot be elaborated completely. In addition, the operation speed of the semiconductor device has to be lowered to prevent the device from generating a large amount of heat and the heat cannot be dissipated timely from being occurred, so as to prevent the semiconductor device from being thermally damaged as a result of the excessively high temperature. Moreover, in order to lower the temperature of the semiconductor device, a module composed of semiconductor devices is typically set with a heat-dissipating device, such as a fan and a heat pipe, so that the volume of the semiconductor apparatus and the design complexity of the apparatus are greatly increased to further increase the cost of the product.